The pillow has undoubtedly been with man for longer than recorded history. Most persons prefer to have their head elevated slightly above the level of their body while sleeping. The classic down filled or foam pillows have traditionally been designed as a rectangle or in some cases other shapes have been used such as round, square or other ornamental shapes. Some pillows are even made up of two parts, one being a soft face and the opposite a firmer face.
It is interesting to note that nowhere in the prior art is a recognition that an optimum pillow must take into account that there are two parts of the anatomy which need to be supported by the pillow, namely the neck as well as the head and that each are at a different level when lying on one's back and each require a different degree of support for greatest comfort. The neck is usually supported by the pillow, only if the pillow is soft enough so that the depression caused by the head is sufficient that the neck is supported. Usually the neck is in contact with the pillow but the predominant support is applied to the back of the head and only lesser support is given to the neck. The net result is a slight upward pressure on the neck which can result in discomfort.
Additionally, most pillow designs do not take into account the fact that many persons like to sleep on their side but do not desire that their face and mouth be obstructed. Some very soft pillows actually obstruct the sleepers mouth if they attempt to sleep on their side. At best, the typical average firmness pillow puts significant side pressure on the jaw of the sleeper. This is not recognized by many as a problem except those with a need to wear orthodontic headgear or other with dental or jaw problems. Such persons, heretofore, have not been able to find an acceptable pillow which will allow them to lie on their side while sleeping. I am one of those persons.